1. Field of the Invention
This invention relates in general to poultry processing. More particularly, this invention relates to a system and method of processing poultry using electrolyzed water.
2. Background of the Invention
The Center for Disease Control (CDC) estimates that 76 million cases of food-borne illnesses occur each year, while food poisoning claims the lives of an estimated 5200 Americans. Most cases of food-borne illnesses are related to surface or product contamination, and up to one-third of the illnesses are related to improperly handled poultry and produce. With United States weekly chicken broiler production now exceeding 150 million birds per week, and with over 9 billion birds processed each year, a significant challenge for poultry processors is the control of illness-causing pathogens, including Salmonella and E. coli. 
The current method of controlling illness-causing pathogens in poultry processing utilizes antimicrobial sprays and washes, followed by quenching in a chiller. The two antimicrobial agents most commonly used to disinfect poultry carcasses prior to the chiller are sodium hypochlorite and trisodium phosphate, while chlorine and chlorine dioxide gases are bubbled into chiller water in an attempt to kill pathogens there. These disinfectants are increasingly ineffective in preventing cross-contamination in vats and chillers during processing. They are also toxic to plant workers and the environment. Chlorine off gassing poses a threat to worker health. Trisodium phosphate contaminates wastewater with dangerous phosphates that cannot be removed.
The monetary cost associated with the current methods of poultry processing are just as high as the costs to workers and the environment. Large quantities of chemicals must be purchased and disposed of. For instance, each poultry processing facility in the United States uses up to 7,500 gallons of toxic chlorinated water every hour. Thus processing plants pay twice: first for the chemicals and then for expensive wastewater management solutions. The shortcomings and expense of the disinfectants currently used by poultry processors attest to a real need for effective cleaning and disinfecting alternatives.
Electrolyzed water is useful for disinfecting and cleaning. Electrolyzed water is produced by electrolysis. A feed water solution containing a saline solution component is supplied to an electrolytic cell comprising both an anode chamber and a cathode chamber. When normal culinary tap water is combined with an electrolyte (i.e., salt) and placed in contact with an electrical probe or plate, electrolysis occurs once the probe or plate is electrically charged by a power source. The probes or plates are separated by a membrane that separates and isolates certain chemical ions. During the chemical reaction, positively charged ions naturally migrate to the negative electrode (i.e., cathode) and negatively charged ions including precursors for hypochlorous acid (HOCl) naturally migrate towards the positive electrode (i.e., anode). The feed water solution is cathodically electrolyzed in the cathode chamber to produce electrolyzed water as an antioxidant solution called alkaline catholyte, commonly referred to as Type B water. The feed water solution is anodically electrolyzed in the anode chamber to produce electrolyzed water as an oxidant solution called anolyte, whose pH is modified in the process, and is commonly referred to as Type A water. The anolyte is a strong oxidizing solution. More specifically, acidic electrolyzed water is normally generated from the anode electrode through electrolysis of a dilute aqueous sodium chloride (NaCl) solution. The Cl−1 ions are electrochemically oxidized to Cl2 gas on the anode surface, which gas is partially hydrolyzed to hypochlorous acid (HOCl) in solution phase and to other ions.
The relatively high bactericidal activity of acidic electrolyzed water, or Type A water, is attributed to high oxidation-reduction potential (ORP), presence of dissolved Cl2, OCl−, and HOCl, and acidic pH. The high ORP of Type A water kills microbes by first damaging cell walls, thus allowing infiltration of the water solution inside the cell walls and causing an osmotic or hydration overload. The Type A water floods the cell faster than the cell can expel the fluid thus causing the cell to burst. Also contributing to the relatively high bactericidal activity is the presence of so-called active chlorine, which comprises dissolved Cl2, OCl−, and HOCl. The bactericidal activity of dissolved Cl2 lessens over time as it evaporates or is otherwise lost from the Type A water during storage or a period of treatment. This loss may also affect other important properties of Type A water, such as its pH, ORP, and HOCl concentration. Finally, the low pH of Type A water effectively kills many pathogens.